Hatching device



G. BAER HATCHING DEVICE Nov. 9, 1948.

Filed June 27, 1946 0S Zrwjziw' 6'. wel@ EN sn/T Patented Nov. 9, 1948HATCHING DEVICE Georges Baer, Paudex-Lausanne, Switzerland ApplicationJune 27, 1946, Serial No. 679,699 In Switzerland January 30, 1946 1Claim.

The object of the present invention is an improved hatching device. Thisdevice is intended to control the motion of a rule parallel to itself byequal successive displacements. An important feature of the inventionresides in that a movable foot adhering by friction on the surface ofthe drawing is linked with the rule by an extensible arm apt to beshortened by any predetermined amount by pressure on a control element.

The attached drawing represents by way of eX- ample an embodiment of theinvention.

Fig, 1 is a plan view thereof.

Fig. 2 is an elevation view corresponding to Fig. 1.

Fig. 3 is a partial section in larger scale of a detail according toline III-III of Fig, 2.

Fig. 4 shows a mode of utilization of the described device.

In the embodiment shown, the device comprises a foot I, intended to reston the surface to be hatched, and a link 2 intended to be fixed on amovable rule, The link is connected to the foot by an articulatedtriangle the larger side of which is constituted by a control lever 3carrying a press-button 4, the smaller side being formed by a rod 5 andthe medium side comprising a micrometric screw 6 with graduated nut 1.This graduation cooperates with an index 8 traced on a strut 9articulated on link 2 and in which the screw can slide axially. A springlocated in a barrel I closed by a muif II applies the nut against thestrut by letting the barrel slide in its muff. A graduation I2 traced onthe barrel and cooperating with the free edge of the muil II indicatesapproximately the free run of the screw in the strut, whereas themicrometric graduation of the nut enables to complete the reading withaccuracy.

The link 2 is U-shaped and dove-tailed, so as to be apt to fit into aboss adapted to that effect on the movable rule. The foot I carries aringshaped rubber washer covering a Wide inscribed area for insuring thestability, but presenting only a small contacting surface for increasingthe adherence.

The operation of this device is as follows:

One places the device as shown in Fig. 4, the link 2 plugged into a bossadapted on the rule, and the foot I resting on the drawing. One adjuststhe nut in such a Way that the graduation I2 and that of the nutindicate the spacing which is to be obtained between adjacent hatchinglines. For hatching, it suffices to press lightly on the rule with a fewfingers of the left hand, whilst the palm or the thumb of this same handoperates the press-button 4 after the tracing of each hatching line. Thepressure of the button causes the set-back of the rule by the play oflever 3 and rod 5, the foot being applied on the drawing and adheringmomentarily thereto. When one releases the button, the relieved footslides on the drawing, whereas the rule, still maintained under a slightpressure on the fingers, adheres in its turn on the drawing and so on.

The foot intended to rest on the drawing can present small points insuch number and shape that they adhere to the surface of the drawingwithout sinking into it, and distributed over a large area in order togive stability.

What I claim is:

A hatching device for controlling the motion of a rule parallel toitself by equal successive displacements, comprising in combination amovable foot adapted to adhere by friction on the surface of a drawing,a removable support rigidly adaptable on the rule, an extensible armlinking said movable foot with said support, means for shortening saidextensible arm by any predetermined amount by pressure thereon, saidextensible arm comprising a threaded shaft slidable through saidremovable support and screwed by its one end in a sleeve hingedlycarried by said foot and by its other end in a nut with micrometricscale, said nut acting on the one hand as rest abutment maintaining saidarm in its extended position under the action of a spiral spring woundon said shaft, and enabling on the other hand, by suitable rotation,modifying the length of said arm to adjust the run of said movable footand consequently the rule.

GEORGES BAER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 141,029 Blunck July 22, 1873393,290 Both Nov. 20, 1888 740,871 Kastmann Oct. 6, 1903

